1. Field of the Invention
This application relates to medical instruments generally, and in particular relates to injection systems for intraosseous and or dental injection of medical solution.
2. Description of the Related Art
Intraosseous injection of anesthetic is a commonly used technique to provide a small amount of anesthetic solution to a localized area, such as the jawbone of a patient for a dental or endodontic procedure. In some cases, anesthetic solution is delivered in the trabecular bone rather than delivering the anesthesia to the soft tissue of the patient. Using an intraosseous injection system can result in profound anesthesia in less than thirty seconds, while delivery of anesthetic solution to the soft tissue can take more than seven minutes for the anesthetic to take effect.
Intraosseous injection requires the perforation of the cortical plate, which is very hard. Some intraosseous injection systems have disadvantages in the perforation or injection process. Some systems require the use of at least two tools, a perforator and a separate injector needle, making the injection procedure complicated and time consuming. With some systems, it is difficult to find the initial hole created by the perforator to inject the anesthetic. In some cases where a guide sleeve is used, the guide sleeve can be difficult to remove. Some systems have a needle that serves both as a perforator and an injector, however, these systems often become clogged with bone chips which can prevent the injection of the anesthetic solution.
Some endodontic techniques require tool rotation to penetrate the site. A needle, a perforator, a file, or another endodontic tool can be connected to an intermediate component to engage a driving device. In some systems, the tools tend to heat up during cortical plate penetration and can wear-out prematurely. Excessive heat generated during cortical plate penetration can cause the intermediate component holding the needle or perforator to meltdown and in some cases detach from the needle or perforator. The detached needle or perforator can lead to further complications. In some cases, driving devices having motorized portions can break the tools by applying excessive torque to the tool.
Some intraosseous injection systems require an intermediate piece to transfer anesthetic from an ampoule to the needle. Some intraosseous injection systems have a static needle arrangement where it is difficult and/or time consuming to replace the needle and may increase the risk of needle-prick injuries. For example, some syringe connections have threaded features that require turning a hub several times for attaching or removing a needle from the system.
Additionally, safety concerns generally call for capping the needle for transport to or from the point of use. Some needle receptacles have covering mechanisms, such as shields, that require the end user to push them down to cover the needle after the needle is used. However, in some systems, the needle is not shielded at all times and the chances of injury still exist. For example, the end user is less protected after the cap or other covering mechanism is removed or withdrawn. Exposure of the needle increases the chances of pricking the patient and/or the end user.